libstdc++
splay_fn_imps.hpp
Go to the documentation of this file.
1 // -*- C++ -*-
2 
3 // Copyright (C) 2005-2020 Free Software Foundation, Inc.
4 //
5 // This file is part of the GNU ISO C++ Library. This library is free
6 // software; you can redistribute it and/or modify it under the terms
7 // of the GNU General Public License as published by the Free Software
8 // Foundation; either version 3, or (at your option) any later
9 // version.
10 
11 // This library is distributed in the hope that it will be useful, but
12 // WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 // General Public License for more details.
15 
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
19 
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 // <http://www.gnu.org/licenses/>.
24 
25 // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
26 
27 // Permission to use, copy, modify, sell, and distribute this software
28 // is hereby granted without fee, provided that the above copyright
29 // notice appears in all copies, and that both that copyright notice
30 // and this permission notice appear in supporting documentation. None
31 // of the above authors, nor IBM Haifa Research Laboratories, make any
32 // representation about the suitability of this software for any
33 // purpose. It is provided "as is" without express or implied
34 // warranty.
35 
36 /**
37  * @file splay_tree_/splay_fn_imps.hpp
38  * Contains an implementation class for splay_tree_.
39  */
40 
41 #ifdef PB_DS_CLASS_C_DEC
42 
43 PB_DS_CLASS_T_DEC
44 void
45 PB_DS_CLASS_C_DEC::
46 splay(node_pointer p_nd)
47 {
48  while (p_nd->m_p_parent != base_type::m_p_head)
49  {
50 #ifdef _GLIBCXX_DEBUG
51  {
52  node_pointer p_head = base_type::m_p_head;
53  assert_special_imp(p_head, __FILE__, __LINE__);
54  }
55 #endif
56 
57  PB_DS_ASSERT_BASE_NODE_CONSISTENT(p_nd)
58 
59  if (p_nd->m_p_parent->m_p_parent == base_type::m_p_head)
60  {
61  base_type::rotate_parent(p_nd);
62  _GLIBCXX_DEBUG_ASSERT(p_nd == this->m_p_head->m_p_parent);
63  }
64  else
65  {
66  const node_pointer p_parent = p_nd->m_p_parent;
67  const node_pointer p_grandparent = p_parent->m_p_parent;
68 
69 #ifdef _GLIBCXX_DEBUG
70  const size_type total =
71  base_type::recursive_count(p_grandparent);
72  _GLIBCXX_DEBUG_ASSERT(total >= 3);
73 #endif
74 
75  if (p_parent->m_p_left == p_nd &&
76  p_grandparent->m_p_right == p_parent)
77  splay_zig_zag_left(p_nd, p_parent, p_grandparent);
78  else if (p_parent->m_p_right == p_nd &&
79  p_grandparent->m_p_left == p_parent)
80  splay_zig_zag_right(p_nd, p_parent, p_grandparent);
81  else if (p_parent->m_p_left == p_nd &&
82  p_grandparent->m_p_left == p_parent)
83  splay_zig_zig_left(p_nd, p_parent, p_grandparent);
84  else
85  splay_zig_zig_right(p_nd, p_parent, p_grandparent);
86  _GLIBCXX_DEBUG_ASSERT(total ==this->recursive_count(p_nd));
87  }
88 
89  PB_DS_ASSERT_BASE_NODE_CONSISTENT(p_nd)
90  }
91 }
92 
93 PB_DS_CLASS_T_DEC
94 inline void
95 PB_DS_CLASS_C_DEC::
96 splay_zig_zag_left(node_pointer p_nd, node_pointer p_parent,
97  node_pointer p_grandparent)
98 {
99  _GLIBCXX_DEBUG_ASSERT(p_parent == p_nd->m_p_parent);
100  _GLIBCXX_DEBUG_ASSERT(p_grandparent == p_parent->m_p_parent);
101 
102  PB_DS_ASSERT_BASE_NODE_CONSISTENT(p_grandparent)
103 
104  _GLIBCXX_DEBUG_ASSERT(p_parent->m_p_left == p_nd &&
105  p_grandparent->m_p_right == p_parent);
106 
107  splay_zz_start(p_nd, p_parent, p_grandparent);
108 
109  node_pointer p_b = p_nd->m_p_right;
110  node_pointer p_c = p_nd->m_p_left;
111 
112  p_nd->m_p_right = p_parent;
113  p_parent->m_p_parent = p_nd;
114 
115  p_nd->m_p_left = p_grandparent;
116  p_grandparent->m_p_parent = p_nd;
117 
118  p_parent->m_p_left = p_b;
119  if (p_b != 0)
120  p_b->m_p_parent = p_parent;
121 
122  p_grandparent->m_p_right = p_c;
123  if (p_c != 0)
124  p_c->m_p_parent = p_grandparent;
125 
126  splay_zz_end(p_nd, p_parent, p_grandparent);
127 }
128 
129 PB_DS_CLASS_T_DEC
130 inline void
131 PB_DS_CLASS_C_DEC::
132 splay_zig_zag_right(node_pointer p_nd, node_pointer p_parent,
133  node_pointer p_grandparent)
134 {
135  _GLIBCXX_DEBUG_ASSERT(p_parent == p_nd->m_p_parent);
136  _GLIBCXX_DEBUG_ASSERT(p_grandparent == p_parent->m_p_parent);
137 
138  PB_DS_ASSERT_BASE_NODE_CONSISTENT(p_grandparent)
139 
140  _GLIBCXX_DEBUG_ASSERT(p_parent->m_p_right == p_nd &&
141  p_grandparent->m_p_left == p_parent);
142 
143  splay_zz_start(p_nd, p_parent, p_grandparent);
144 
145  node_pointer p_b = p_nd->m_p_left;
146  node_pointer p_c = p_nd->m_p_right;
147 
148  p_nd->m_p_left = p_parent;
149  p_parent->m_p_parent = p_nd;
150 
151  p_nd->m_p_right = p_grandparent;
152  p_grandparent->m_p_parent = p_nd;
153 
154  p_parent->m_p_right = p_b;
155  if (p_b != 0)
156  p_b->m_p_parent = p_parent;
157 
158  p_grandparent->m_p_left = p_c;
159  if (p_c != 0)
160  p_c->m_p_parent = p_grandparent;
161 
162  splay_zz_end(p_nd, p_parent, p_grandparent);
163 }
164 
165 PB_DS_CLASS_T_DEC
166 inline void
167 PB_DS_CLASS_C_DEC::
168 splay_zig_zig_left(node_pointer p_nd, node_pointer p_parent,
169  node_pointer p_grandparent)
170 {
171  _GLIBCXX_DEBUG_ASSERT(p_parent == p_nd->m_p_parent);
172  _GLIBCXX_DEBUG_ASSERT(p_grandparent == p_parent->m_p_parent);
173 
174  PB_DS_ASSERT_BASE_NODE_CONSISTENT(p_grandparent)
175 
176  _GLIBCXX_DEBUG_ASSERT(p_parent->m_p_left == p_nd &&
177  p_nd->m_p_parent->m_p_parent->m_p_left == p_nd->m_p_parent);
178 
179  splay_zz_start(p_nd, p_parent, p_grandparent);
180 
181  node_pointer p_b = p_nd->m_p_right;
182  node_pointer p_c = p_parent->m_p_right;
183 
184  p_nd->m_p_right = p_parent;
185  p_parent->m_p_parent = p_nd;
186 
187  p_parent->m_p_right = p_grandparent;
188  p_grandparent->m_p_parent = p_parent;
189 
190  p_parent->m_p_left = p_b;
191  if (p_b != 0)
192  p_b->m_p_parent = p_parent;
193 
194  p_grandparent->m_p_left = p_c;
195  if (p_c != 0)
196  p_c->m_p_parent = p_grandparent;
197 
198  splay_zz_end(p_nd, p_parent, p_grandparent);
199 }
200 
201 PB_DS_CLASS_T_DEC
202 inline void
203 PB_DS_CLASS_C_DEC::
204 splay_zig_zig_right(node_pointer p_nd, node_pointer p_parent,
205  node_pointer p_grandparent)
206 {
207  _GLIBCXX_DEBUG_ASSERT(p_parent == p_nd->m_p_parent);
208  _GLIBCXX_DEBUG_ASSERT(p_grandparent == p_parent->m_p_parent);
209  PB_DS_ASSERT_BASE_NODE_CONSISTENT(p_grandparent)
210  _GLIBCXX_DEBUG_ASSERT(p_parent->m_p_right == p_nd &&
211  p_nd->m_p_parent->m_p_parent->m_p_right == p_nd->m_p_parent);
212 
213  splay_zz_start(p_nd, p_parent, p_grandparent);
214 
215  node_pointer p_b = p_nd->m_p_left;
216  node_pointer p_c = p_parent->m_p_left;
217 
218  p_nd->m_p_left = p_parent;
219  p_parent->m_p_parent = p_nd;
220 
221  p_parent->m_p_left = p_grandparent;
222  p_grandparent->m_p_parent = p_parent;
223 
224  p_parent->m_p_right = p_b;
225  if (p_b != 0)
226  p_b->m_p_parent = p_parent;
227 
228  p_grandparent->m_p_right = p_c;
229  if (p_c != 0)
230  p_c->m_p_parent = p_grandparent;
231 
232  base_type::update_to_top(p_grandparent, (node_update*)this);
233  splay_zz_end(p_nd, p_parent, p_grandparent);
234 }
235 
236 PB_DS_CLASS_T_DEC
237 inline void
238 PB_DS_CLASS_C_DEC::
239 splay_zz_start(node_pointer p_nd,
240 #ifdef _GLIBCXX_DEBUG
241  node_pointer p_parent,
242 #else
243  node_pointer /*p_parent*/,
244 #endif
245  node_pointer p_grandparent)
246 {
247  _GLIBCXX_DEBUG_ASSERT(p_nd != 0);
248  _GLIBCXX_DEBUG_ASSERT(p_parent != 0);
249  _GLIBCXX_DEBUG_ASSERT(p_grandparent != 0);
250 
251  const bool grandparent_head = p_grandparent->m_p_parent == base_type::m_p_head;
252 
253  if (grandparent_head)
254  {
255  base_type::m_p_head->m_p_parent = base_type::m_p_head->m_p_parent;
256  p_nd->m_p_parent = base_type::m_p_head;
257  return;
258  }
259 
260  node_pointer p_greatgrandparent = p_grandparent->m_p_parent;
261 
262  p_nd->m_p_parent = p_greatgrandparent;
263 
264  if (p_grandparent == p_greatgrandparent->m_p_left)
265  p_greatgrandparent->m_p_left = p_nd;
266  else
267  p_greatgrandparent->m_p_right = p_nd;
268 }
269 
270 PB_DS_CLASS_T_DEC
271 inline void
272 PB_DS_CLASS_C_DEC::
273 splay_zz_end(node_pointer p_nd, node_pointer p_parent,
274  node_pointer p_grandparent)
275 {
276  if (p_nd->m_p_parent == base_type::m_p_head)
277  base_type::m_p_head->m_p_parent = p_nd;
278 
279  this->apply_update(p_grandparent, (node_update*)this);
280  this->apply_update(p_parent, (node_update*)this);
281  this->apply_update(p_nd, (node_update*)this);
282  PB_DS_ASSERT_BASE_NODE_CONSISTENT(p_nd)
283 }
284 #endif